High-intensity pulsed laser radiation is used to modify surfaces of materials and fabricate technologically desirable structures on a micrometer and sub-micrometer level. Besides their technological importance, such surface modifications are currently of substantial scientific interest. Although adequate, current processes used for such irradiation surface modifications are relatively complex, involve several steps, and are non-equilibrium due to high heating and cooling rates. Also, there are large temperature gradients, and a variety of thermal, chemical and photochemical transformations that can occur. Such processes and their interplay are often not fully understood, providing a need for systematic studies of laser irradiation of materials as a function of irradiation parameters.
Thus, improved, reliable, simple and low-cost techniques for fabrication of micro-structures and nano-structures having nano-tips of silicon and other semiconductor and metal materials are needed. Moreover, relatively large, high-density arrays of such nano-tips, are desirable in a number of electron field emission applications.